1. Field of the Invention
The present invention pertains to the art of dishwashers and, more particularly, to the incorporation of a detergent dispensing system structured to establish a timed delay for the introduction of detergent during a washing operation.
2. Discussion of the Related Art
In a typical dishwasher, a detergent dispenser is provided in a washing chamber to house a detergent. The compartment is loaded with detergent and includes a cover which is initially, manually closed and then subsequently, automatically opened to dispense detergent directly into the washing chamber of the dishwasher during a predetermined stage of a washing operation. Many attempts have been made in the art of dishwashers to provide improved detergent dispersion and effectiveness. For instance, it is also known to direct a cleaning agent from a dispenser directly into a spray arm, such as demonstrated by UK Patent Application No. GB 2321590 and U.S. Pat. No. 5,235,994, or to impinge washing fluid from a rotating spray arm directly into an exposed dispenser container to slowly dissolve and distribute a cleaning agent, such as demonstrated by International Publication WO 2009/083576.
In connection with improving an overall washing operation, it is also known in the art to provide a variety of spray units for the washing fluid. That is, in addition to rotary arms, it is known to provide fixed spray heads. For instance, U.S. Pat. Nos. 7,445,013 and 7,475,696 are concerned with providing one or more additional spray units which can establish certain wash zones with a dishwasher. Even when all of the spray units are slated to be employed for a selected washing operation, the activation of the different ones or sets of the spray units are generally, sequentially timed for various reasons, such as to maintain sufficient water pressure.
It can also be desirable to incorporate an auxiliary dispenser to increase the concentration washing agent in order to enhance the performance of the dishwasher. In fact, this broad concept is disclosed in the '696 patent listed above. In general, with such known arrangements, whenever washing fluid is directed to a specified spray unit having an auxiliary dispenser, additional detergent from the dispenser is added to the washing fluid. Unfortunately, there may exist certain scenarios wherein washing fluid is slated to be directed to a particular spray unit multiple times during an overall washing operation and it is only desired to provide for the additional detergent dispensing during a single operational phase of the spray unit. With this in mind, despite various known prior art designs, there is still seen to be a need in the art of dishwashers for a dishwasher cleaning agent dispenser system configured to timely release detergent for a given washing operation. In particular, it is seen as beneficial to provide an auxiliary dispenser that can be easily accessed by a user and selectively utilized to aide in the cleaning of heavily soiled kitchenware by quickly and effectively distributing a chemical agent within an intensified wash zone in a timed manner during a washing operation in a dishwasher.